We present photometric and spectroscopic observations of the eclipsing binary system BI CVn. Wilson-Devinney analysis of its light and radial velocity curves showed that the system is a W-subtype overcontact W-UMa type binary. We computed the absolute physical parameters of the system based on a mass ratio spectroscopically determined in this study. Though the orbital period had changed somehow in the past, it has remained constant for a long time since March 1999, contradicting the previous interpretations suggesting a cyclic variation superimposed on a quadratic change.

Keywords

• (Stars:) binaries: eclipsing;
• Stars: fundamental parameters;
• Stars: individual (BI CVn)